adjective

obtuse

Having an angle greater than 90 degrees but less than 180 degrees.

An obtuse angle is wider than a right angle.

Etymology

Latin obtusus means blunted. Geometry uses that bluntness for an angle wider than a right angle, contrasting with the sharpness of an acute angle.

More examples

  • The triangle had one obtuse angle.
  • She opened the hinged arms to an obtuse angle.
  • The diagram marked the obtuse angle in blue.

Forms

obtuse · more obtuse · most obtuse

Similar words

acute
An acute angle is less than 90 degrees; an obtuse angle is greater than 90 and less than 180.
reflex
A reflex angle exceeds 180 degrees; an obtuse angle does not.